Lubricant



Patented Apr. 30, 1940 UNMED STATES PATENT OFFICE LUBRICANT 24 Claims.

This invention relates to lubricants and particularly to viscous hydrocarbon oils having incorporated therein materials for improving their properties.

It is well known that viscous hydrocarbon oils, particularly when employed as lubricants in internal combustion engines-and in transformers, deteriorate during service, such deterioration being the result of the action of oxygen, heat, moisture and the catalytic effect of bearing metals. Such deterioration generally results in the formation of sludge of indefinite composition and of acidic products which are frequently highly corrosive to the metals and alloys with which they come in contact during lubrication. The formation of corrosive products is particularly noticeable in highly refined oils which, however, possess very desirable characteristics in other respects, notably in their viscosity-temperature relationships, and in reduced tendency to carbon formation. Therefore, it has long been desired to eliminate theformation of sludge and corrosive products in the oils, and many proposals have been made by those skilled in the art for the solution of such problem.

It is an object of the present invention to produce viscous hydrocarbon oils having improved stability against deterioration and reduced tendency to form corrosive products, particularly when subjected to the conditions of service present in internal combustion engines. Another object is to produce viscous hydrocarbon oils having a greatly reduced tendency to corrode metals and alloys with which they come into contact during service. A further object is to provide a method for producing such improved viscous hydrocarbon oils. A still further object is to provide a method of lubricating certain alloy bearings without corroding-such hearings to an objectionable extent. Still other objects are to provide new compositions of matter and to advance the art. Other objects will appear hereinafter.

The above and other objects may be accomplished in accordance with my invention which comprises incorporating in viscous hydrocarbon oils a small proportion of at least one compound consisting of carbon, hydrogen, nitrogen and ethereal oxygen having the formula R(X) wherein R represents a pyridine or quinoline No Drawing. Application April 5, 1938, Serial No. 200,071

(or. s'l-t) nucleus, Y is an integerfrom 1 to 3, preferably 1, and X is a radical containing a tertiary nitrogen connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms, and which radical X is selected from tertiary alkylamines, 5 N-alkyl pyrrole's, N-alkyl piperidines and pyridines. It will befound that the resulting product will have a greatly decreased tendency to deteriorate and form sludge or corrosive products in use, particularly under the conditions occurring 10 in internal combustion engines.

By the term viscous hydrocarbon oil, I mean a. hydrocarbon oil having'viscosities within the range employed for lubricating metallic bearing surfaces moving relatively to each other and mutually carrying a load. The preferred oils will be the lubricating oils obtained from petroleum.

By the term "ethereal oxygen, it will be understood that I mean the oxygen which is essential to every ether and has both valences satisfied by carbon atoms of organic radicals which form with the oxygen an ether.

The term consisting of carbon, hydrogen, nitrogen and ethereal oxygen shall be understood to be generic and to include compounds which do not contain ethereal oxygen as well as those which do contain ethereal oxygen.

By the term tertiary alkylamines, I mean amines which are aliphatic in nature and intend to exclude amines containing a benzene ring.

While compounds falling within the formula R(X) as heretofore defined, will be effective for my purpose, I have found that those compounds in which X represents a pyridine ring and an N-alkyl piperidine group are the most effective and represent the preferred embodiments of my invention. Also, while the nuclei of R and X may contain substituents such as alkyl, aryl, aryloxy and amino radicals, and particularly methyl, 40 ethyl, isopropyl, methoxy and butoxy groups, preferably, such nuclei are unsubstituted. Amongst the compounds of my invention, I have found that alpha, alpha'-dipyridyl, a mixture of dipyridyls, a mixture of 4-(diand tri-piperidylmethyl) -methylquinoline, 4- (beta-piperidylethyl) -quinoline and 4-(beta-piperidylethyl)-6-methoxyquinoline are particularly effective for my purpose. Mixtures of compounds, such as those generally obtained in the synthesis thereof, appear so formulae:

LN NJ p m-alphN-dipyrldyl CHI-CH:

CH -C Hr-N C Hr-C:

N a-(beta-piperidyletliyl) quinoline oar-om CHs-CHr-N CHrC! orno N 4 -(beta-piperidylethyl)-6-methoxy-quinolins The compounds of my invention may be employed in purified form or as the crude product. They may be employed with other lubricant addition agents such as compounds for depressing pour points, increasing film strength or-improving the viscosity index of theoils. The amount of compound to be employed with the lubricating oil may vary from about 0.02 to about 10% based on the oil. Larger amounts may be employed, but without advantage. Preferably, my compounds are employed in the proportion of about 0.10 to 2.0% based on the oil. The use of my compounds is not restricted to liquid oils, but they may be employed in greases or'other lubri-' eating media of petroleum origin.

In order to more clearly illustrate my invention, the general methods of preparing my compounds, the preferred mode of carrying my invention into effect and the advantageous results to be obtained thereby, the following examples are given:

Example! Two thousand grams of pyridine and 1833 grams anhydrous ferric chloride were mixed and placed in a glass-lined autoclave which was then heated at 320 to 350 C. for seven hours. On cooling, the mixture was crushed, made strongly alkaline with potassium hydroxide, and steam distilled. The distillate, after acidification with sulfuric acid, was concentrated to one-tenth its original volume and made alkaline with potassium hydroxide. A considerable quantity of solid which separated was removed by filtration and the filtrate extracted several times with ether. The ether layers were dried and distilled, the unreacted pyridine distilling with the lower boiling fractions. The high boiling fraction solidifled and, together with the solid which had previously been separated, was crystallized from petroleum naphtha. One hundred and eighty-six grams of product melting at 70 to 72 C. was

' obtained which was, alpha, alpha'-dipyridyl.

Example 2 a .action mixture was decomposed with cc. wa-

ter and the oily layer distilled. The fraction boiling below C. was discarded while a fraction boiling between 150 and 200 C. was washed with water, dried over sodium sulfate. and added to the residue remaining from the distillation. From these combined materials a total of 35 grams of material boiling between 200 and 350 C. was obtained. This consisted essentially of a mixture of isomeric dipyridyls.

Example 3 Twenty and three-tenths grams of 3'? per cent formaldehyde were neutralized with aqueous sodium hydroxide and added with cooling to 21.3 grams piperidine. Thirty-eight and five-tenths grams lepidine were then added and the mixture heated in a sealed tube to 120 C. for sixteen hours. extracted with several portions of ether, the ether solutions dried over anhydrous potassium carbonate, concentrated, and distilled under reduced pressure. Twenty-two grams of material boiling at to 178 C. at 3.5 mm. was obtained, which appears to be 4-(beta-piperidylethyD- quinoline. An additional 9.5 grams of material boiling at 200 to 210 C. at 3.5 mm. was obtained which appears to be a mixture. of the 4-(diand tripiperidylmethyl)-methylquinoline.

The efl'ectiveness of the compounds of the type given above was determined by a procedure similar to that described in the Analytical Edition of Industrial and Engineering Chemistry, volume 6, page 419 (1934), modified by suspending in the oil strips which had been cut from cadmiumsilver bearings and-placed in such a fashion that the strips were completely immersed while the air which was bubbled through the oil washed over the exposed surfaces. In this test, a volume of 300 cc. of oil was used through which washed air was bubbling at a rate of ten liters per hour, the oil temperature being maintained at 171 to 172 C. The cadmium-silver strip was removed at various intervals and weighed. From the curve showing loss in weight against time,

there was determined the time required for a loss amount of insoluble material which precipitated out on standing.

Example 4 The effectiveness of alpha, alpha'-dipyridyl in eliminating the formation of corrosive products was determined in the above test using a solvent extracted paraflin base oil with a viscosity at 210? F3015 46.8 seconds Saybolt Universal.

Concentration of Hours to Sludge alter Viscosity at alpha, slpha'- di l0 mgJsq in 41 hrs. of 210 F. after pyridyl, percent by corrosion of test mg./l0 157 hrs., weight cadmium-silver gm. seconds None. 30 126. 0 67 Example 5 Themixed dipyridyls and the mixture of (diand tripiperidylmethyl) -methylquinoline were After coolin the reaction product was tested in 0.25% concentration in a solvent extracted Mid-Continent base oil of S. A. E.-30 grade with the following results.

. Hours to 10 Viscosity at Compound added to oil $5425 3, 210 F. alter cadmium-silver 100 of Non 8 99 The efiect of 0.25% concentration of 4-(betapiperidylethyD-quinoline was determined in another sample of solvent extracted Mid-Continent base S. A. E.-3O oil.

v Hours to 10 Viscosity at Compound added to oil g fi hf ff" cadmium-silver I of test None 22 130. 7 4-(beta-piperidyl-etbyl) 'quinoline 187 72. 7

Example 7 I Fifty grams of a commercial paraflln base oil of an S. A. E.-20 W grade, to which had been added 0.5% of the compound under test, was placed in a 125 cc. Erlenmeyer flask. The flask was fitted with a cork stopper containing a 1 mm. capillary tube which extended within $4; inch of the bottom of the flask. Weighed strips, approximately 1% inches by V2 inch, cut from cadmium-silver and copper-lead bearings of the type used in present day internal combustion engines, together with similar strips out from sheets of autobody steel, were suspended in the flask in such a fashion as to be immersedto approximately half their lengths in oil. The unit was placed in an oil bath maintained at substantially 175 C., and air, which had been passed through two wash bottles of distilled water, was bubbled through the capillary tube at a rate of 2.5 to 3.0 liters per hour. The strips of cadmiumsilver and copper-lead bearing metals were removed at intervals and weighed after washing with chloroform and acetone. From the curve of loss of weight against time of exposure,-it was possible to determine the time at which a 10 mg. loss per 10 grams of bearing metal had accurred. The amount of oxidized material in the oil was determined by diluting 10 grams to 100 cc.-

Hour! tol l0 ing/gm. Sludge values 058 Compound added to oil (0.6%)

Cedmium- Copper Hours Mg./10

silver lead of test gm.

None-control 26 24 100 394. 6 Dietbyl-o-phenylenedlamlne 22 26 100 Excessive None-control 23 22 48 112. 8 Sym.-diphenylethylenediam e 23 24 48 144. 1 Alpha, alphel-dipyr 47 Above 45 48 49. d None-control 23 g 24 70 103. 0

Tetramethyl plperazino Below 20 21 70 -'Excessive d-(beta-piperidylethyD-fi-methoxyquiuoline. Above 70 Above 70 70 50. 4

"These samples contained much more sludge than the controls, so much that it could not be filtered out for measurement.

(lJHa CHr-N-CH; N

z-N-dlmetb laminomethyl q noline CHs CH3 CHr-( JH H CHa Gamma, gamma'-diiso ropylelpba,alpha-dip dyl CHE-CH2 0 H2 CR -CH: v

Alpba-piperidylmethylpyridine Alpha, alpbe-dipyridyl methane Alpha, alpha'-dipyrldyl ethane Z-beta-N-dibutylaminoetbyl quinoline I claim:

1. A viscous hydrocarbon oil having. incorporated therein a. small proportion of at least one compound consisting of carbon, hydrogen, nitrogen and ethereal oxygen having the formula BAX) wherein R is. a nucleus of the group consisting of pyridine and quinoline nucelei, Y is an integer from 1 to 3 and X is a radical containing .nected to a carbon of the pyridine ring of R'.

a .tertiary nitrogen connected to a carbon of the pyridine ring of R through from 1 to 3'carbon atoms and which radical is a member of the group consisting of tertiary alkyl amines, N-

alkyl pyrroles, N-alkvl piperidines and pyridines; 2. A viscous hydrocarbon oil having incorporated therein a small portion of at least one compound consisting of carbon, hydrogen, nitrogen and ethereal oxygen having the formula R(X)y wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei, Y is "an integer from 1 to 3 and X is an N-alkyl piperidine radical in which the tertiary nitrogen is conthrough from 1 to 3 carbon atoms.

3. A viscous hydrocarbon oil having incorporated therein a small proportion of at least one compound consisting of carbon, hydrogen, nitrogen and ethereal oxygen having the formula RX wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei and X is a radical containing a tertiary nitrogen connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms and which radical is a memnucleus of the group consisting of pyridine and quinoline nuclei, and X is an N-alkyl piperidine radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of through from 1 to 3 carbon atoms.

5. A viscous hydrocarbon oil having incorporated therein a smallproportion of at least one compound consisting .of carbon, hydrogen and nitrogen having the formula R(X)g wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei, Y is an integer from 1 to 3 and X is a pyridine radical in which the tertiary nitrogen is connected toa carbon of the pyridine ring of R through from 1 to 3 carbonatoms.

6. A viscous hydrocarbon oil having incorporated therein a small proportion of at least one compound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei and X is a pyridine radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms, g

'7-. A viscous hydrocarbon oil having incorpo-' rated therein a small, proportion of at least one dipyridyl.

8. A viscous hydrocarbon oil having incorporated therein a small proportion of a mixture of dipyridyls. 9. A method of lubricating metallic bearing surfaces, which comprises maintaining between the 'bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead,

a film of lubricating oil which initially produces an effective lubricatingqaction but which would normally tend to corrode the aforesaidsurface the corrosion, at least one compound consisting of carbon, hydrogen, nitrogen and ethereal oxygen having the formula R(X) wherein R is a nucleus of the groupconsisting of pyridine and quinoline nuclei, Y is an integer from 1 to 3 and X is a radical containing atertiary nitrogen connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms and which radical is a member of the group consisting'of tertiary alkyl amines, N-alkyl pyrroles, N-alkyl piperidines and pyridines.

10. A 'method of lubricating metallic bearing surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead, a film of lubricating oil which initially'produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but sufllcient proportion to substantially retard the corrosion, at least one compound consisting of carbon, hydrogen, nitrogen and ethereal oxygen having the formula R(X)y wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei, Y is an integer from 1 to 3 and X is an N-alkyl piperidine radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of R through from '1 to 3 carbon 11. A method of lubricating metallic bearing surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead, a. film of lubricating oil which initially produces an effective lubricating action but I which would normally tend to corrode the aforesaid, surface and'maintaining the effectiveness of the lubricating oil by incorporating therein,

in a small-but suillcient proportion to substan 'tially retard the corrosion, at least one-compound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei and X is a radical containing a tertiary nitrogen connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms and which radical is amember of the group consisting of tertiary alkyl amines, N-.-alkyl pyrroles, Nalkyl piperidines and pyridines. a

12. A method of lubricating metallic hearing surfaces which comprises maintaining between the bearing surfaces, one of which conpound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei, and X is an N-alkyl piperidine radical in which the teritary nitrogen is connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms.

l 13. A method of lubricating metallic bearing surfaces which comprises maintaining between the bearing surfaces, one of whichcontains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead, a' film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but sufficient proportion to substantially retard the corrosion, at least one compound consisting of carbon, hydrogen and nitrogen having the formula R(X)y wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei, Y is an integer from 1 to 3 and X is a pyridine radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of R through from 1 to 3- carbon atoms.

14. A method of lubricating metallic bearing surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but suiiicient proportion to substantially retard the corrosion, at least one compound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a nucleus of the group consisting of pyridine and quinoline nuclei and X is a pyridine radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of R through from 1 to 3 carbon atoms.

15. A method of lubricating metallic bearin surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of-cadmium, silver, copper and lead, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrodethe aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but sufficient proportion to substantially retard the corrosion, at least one dipyridyl.

16. A method of lubricating metallic bearing surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the. group consisting of cadmium, silver, copper and lead, a. film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but sufficient proportion to substantially retard the corrosion, a mixture of dipyridyls.

17. A viscous hydrocarbon oil having incorporated therein a small-proportion of a compound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a quinoline nucleus and X is an N-alkyl piperidin'e radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of the quinoline nucleus through from 1 to 3 carbon atoms.

18. A viscous hydrocarbon oil having incorporated therein a small proportion of 4-(betapiperidylethyl) -quinoline.

19. A viscous hydrocarbon oil having incorporated therein a small proportion of a compound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a quinoline nucleus and X is an N-dialkylaminoalkyl radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of the quinoline nucleus through from 1 to 3 carbon atoms.

20. A viscous hydrocarbon oil having incorporated therein a small proportion of 2-beta-N-dibutylaminoethyl quinoline.

21. A method of lubricating metallic. bearing surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but suflicient proportion to substantially retard the corrosion, a compound consisting of carbon, hydrogen and nitrogen having the formula RX wherein R is a quinoline-nucleus and X is an N-alkyl piperidine radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring of the quinoline nucleus through from 1 to 3 carbon atoms.

22. A method of lubricating metallic bearing surfaces which comprises maintaining between the'bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium; silver, copper and lead, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but III sumcient proportion to substantially retard the corrosion, 4- (beta-piperidylethyl) -quinoline.

23. A method of lubricating metallic bearing surfaces which comprises maintaining between the bearing surfaces, one of which contains a characterizing proportion of a metal of the group consisting of cadmium, silver, copper and lead, a

film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid surface and maintaining the effectiveness of the lubricating oil by incorporating therein, in a small but sufficient proportion to substantially retard the corrosion, a compound consisting of carbon, hydrogen and nitrogen having the formula RE wherein R is a quinoline nucleus and x is an N-dialkylaminoalkyl radical in which the tertiary nitrogen is connected to a carbon of the pyridine ring' line.

IRWIN A. DIEI'RICH. 

